Balancing weight for expansion roofs



April 21, 1942. P. s. GRAVER BALANCING WEIGHT FOR EXPANSION ROOFS 2 Sheets-Sheet 1 Filed Jan. 12, 1940 77;/7& 7': i2 4 6 Graver; mwazegw,

April 21, 1942. P. s. GRAVER 2,280,768

BALANCING WEIGHT FOR EXPANSION ROOFS Filed Jan. 12, 1940 2 Sheets-Sheet 2 I N VEN TOR. PM 5 Grave/7 BY Patented Apr. 21, 1942 BALANCING WEIGHT FOR EXPANSION ROOFS Philip S. Graver, Chicago, Ill., assignor to Graver Tank & Mfg. 00., Inc., Oatasauqua, Pa., a corporation of Delaware Application January 12, 1940, Serial No. 313,468

7 Claims.

The invention relates to storage tanks for storing gases or volatile liquids and has reference more particularly to improvements in an expansion root for said tanks which is capable of moving in a vertical direction for varying the vapor space within the tank.

In the expansion roof shown in my Patent No.

2,277,398, granted March 24, 1942, flexible cables are employed for maintaining the roof substantially horizontal during vertical movement thereof and for also preventing undesirable rotation of the roof with respect to the tank. The flexible guide cables are combined with posts of special cross section which depend from the roof and are in turn supported by rollers and sheaves mounted in brackets extending from the side walls of the tank. The sheaves perform a dual function. They provide pulleys for the cables and also guide the posts in their vertical movement with the rise and fall of the roof.

An object of the invention is to provide improved counterbalancing means for use with the depending guide posts, sheaves and rollers of the expansion roof structure disclosed in the application above mentioned.

A more specific object is to provide movable weights for counter-balancing the expansion roof above described in order to reduce the operating pressure and which will have connection with the depending posts by means of flexible connecting chains passing over sheaves in much the same manner as the flexible cables for the roof.

With these and various other objects in view, the invention may consist of certain novel features of construction and operation, as will be more fully described and particularly pointed out in the specification, drawings and claims appended hereto.

In the drawings which illustrate an embodiment of the device and wherein like reference characters are used to designate like parts Figure 1 is a fragmentary sectional view showing the counter-balancing means of the invention 4 applied to an expansion roof having depending with an expansion roof I! having depending guide posts I with which the present counterbalancing means are combined. The side walls ll unite with a base l3 which with the expansion roof I! completes the tank, the base l3 resting directly on the earth or other suitable support. The walls II are reinforced in the upper portion by means of the inwardly directed angle member l5 suitably secured as by welding to the tank walls and which is combined with the angle member Hi to provide structure for supporting the sheaves and rollers for the flexible cables and depending posts to be more particularly described. Also secured to the cylindrical tank walls I I some distance below the angle member ii are brackets ll extending inwardly of the tank and likewise suitably supported by means of spaced angle members 18 and IS. The brackets l! are located at spaced intervals around the inside periphery of the tank wall to conform with the location of the depending posts I4, and below the brackets are positioned supports 20 suitably secured to the side walls of the tank by triangular plates 22 which support the depending posts I4 when the expansion roof is in deflated position.

The outer circumference of the tank at the upper end is provided with a launder 23 formed by the cylindrical member 24 spaced from and concentric with the walls ll of the tank. The launder is completed by the angle member 25 which forms the base of the launder and thus the bottom of the circumferential trough containing the oil or other sealing liquid for sealing the roof with respect to the open top tank. The expansion roof I! has telescoping relation with respect to the cylindrical walls ll of the tank and accordingly the depending skirt 26 has location within the launder. The depending rain shed skirt 2! forms a cover for the launder, protecting the same from the weather. 1

The depending posts it are provided for guiding and controlling the vertical movements of the roof. Said posts are of special cross section, as best shown in Figure 2. When the depending posts have contact with their supporting brackets 20 the roof is in deflated position and said posts accordingly transmit a portion of the weight of the roof to the side walls of the tank. Said posts are arranged in pairs and in cross section each post simulates an H, the flanges thereof having guiding contact with a roller 28 and a sheave 30 rotatably mounted by the upstanding side members 3| which rest on supporting structure provided by the angle members If: and It. The roller 28 and also the sheave 30 have a guiding function with respect to the post and in addition the sheave 30 is adapted to have contact with a flexible cable such as 32. Whereas, one sheave will have a flexible cable 32 passing under the same and which travels upwardly for connection with the expansion roof at 33, the other sheave of the pair will have contact with a cable 34 which passes over the same and continues downwardly, being connected to the lower end of its particular post l4 by means of the hook 35.

During operation of the expansion roof it will be understood that the launder 23 will .contain oil or water as the sealing medium for the depending skirt 25. The space within the cylindrical tank may also contain oil if the tank is being used as a storage tank or the entire space within the same may be used for storing gas. In either case when the pressure exceeds the weight of the roof including the post structure depending therefrom the same will rise and it is this movement of the roof that is controlled by the said depending posts l4 and flexible cables 32 and 34. The cables function to restrain the roof during vertical movement so as to prevent tipping from a horizontal plane. Also the roof is prevented from rotating with respect to the open top tank.

The present invention provides counterbalancing means for the expansion roof, which are combined with the depending posts in much the same manner as the flexible cables. Each bracket I1 is provided with side members 36 which journal a roller 31 and a sheave 38. The flexible chain 40 is adapted to pass over the sheave 38, one depending end supporting the counter-weight 4| and the other depending end connecting with the post l4 by means of the hook 35. Each depending post is therefore additionally guided by a roller 31 and a sheave 38. For accommodating the post each roller is provided with peripheral projections 42 which project within the side flanges of the post. In a similar manner the sheave 38 is provided with projections 43 which have location within the side channels of the post on the side opposite the roller 31.

Movement of the expansion roof l2 may vary considerably, depending on thesize of the tank to which the same is applied and the nature of the liquid stored therein. It is of prime importance that the roof move up and down in a vertical plane and also that the roof be prevented from rotating with respect to the open top tank. This is the function of the depending posts M, the flexible cables 32 and 34 and the sheaves and rollers which have guiding contact with the posts. The counter-balancing weights 4| function to reduce the operating pressure on the roof. The downward pull of the weights is transmitted to the posts and the construction is such that the posts are urged upwardly. The arrangement is materially simplified by the sheaves 38 which support the flexible chains connecting with the counter-weights. Also the operation of each device is materially improved since the sheave will naturally rotate as its particular post l4 moves vertically. It will be observed that the direction of rotation of the sheave as the post moves up and down conforms to that required of the sheave by reason of the flexible chain 40 passing over the same- The guiding contact which each sheave has with its depending post is a natural result of the present construction and the roof is accordingly supported for movement upon very low pressures which takes place with extreme ease and facility.

The invention is not to be limited to or by details of construction of the particular embodiment thereof illustrated by the drawings, as various other forms of the device will of course be apparent to those skilled in the art without departing from the spirit of the invention or the scope of the claims.

What is claimed is:

1. In a storage container for gas or liquid, in combination, an open top tank, an expansion roof for said tank movable with respect thereto to vary the vapor space withinthe tank, a plurality of posts fixed to the roof at circumferentially spaced points and depending within the tank, means supported by the side walls of the tank and having rolling contact with each depending post including a roller and a sheave spaced from each other so that a post passes therebetween, and counter-balancing weights for said expansion roof, each weight having connection with a depending post and the said connecting means passing over one of said sheaves.

2. In a storage container for gas or liquid, in combination, an open top tank, an expansion roof for said tank movable with respect thereto to vary the vapor space within the tank,'a plurality of posts fixed to the roof at circumferentially spaced points and depending within the tank, means supported by the side walls of the tank and having rolling contact with each depending post including a roller and a sheave spaced from each other so that a post passes therebetween, a plurality of counter-balancing weights located within the tank, and flexible means connecting each weight with a depending postwith each flexible means passing over one of said sheaves, whereby the post is urged upwardly by the action of said counter-balancing weights.

3. In a storage container for gas or liquid, in combination, an open top tank, an expansion roof for said tank movable with respect thereto to vary the vapor space within the tank, a plurality of posts fixed to the roof at circumferentially spaced points and depending within the tank, means associated with each post including a roller contacting the upper portion of the post and a roller in contact with the lower portion, a sheave spaced from each roller so that a post passes therebetween, flexible means for maintaining the expansion roof substantially horizontal during vertical movement thereof, said flexible means intermediate their length having contact with certain sheaves, other flexible means passing over the remaining sheaves, and counter-balancing weights carried by said other flexible means.

4. In a storage container for gas or liquid, in combination, an open top tank, an expansion roof for said tank movable with respect thereto to vary the vapor space within the tank, a plurality of posts fixed to the roof at circumferentially spaced points and depending within the tank, means associated with each post including a roller contacting the upper portion of the post and a roller in contact with the lower portion, a sheave spaced from each roller so that a post passes therebetween, flexible means for maintaining the expansion roof substantially horizontal during vertical movement thereof, each flexible means at points intermediate its ends having contact with an upper sheave and each means at one end being secured to the roof and at its other end having connection with a depending post near the lower end thereof, and counterbalancing weights for said expansion roof, each weight having connection with a depending post and the said connecting means passing over a lower sheave,

5. In a storage container for gas or liquid, in combination, an open top tank, an expansion roof for said tank movable with respect thereto to vary the vapor space within the tank, means providing a seal between the tank and roof so as to confine vapors within the tank, a plurality of posts fixed to the roof at circumferentially spaced points and depending within the tank, means having rolling-contact with each post including at least one roller for guiding the post, a sheave spaced from each said roller so that a post passes therebetween, a plurality of counter-balancing weights for said roof, and flexible means supporting each weight and passing over one of said sheaves for connection with its respective depending post, whereby the roof is urged upwardly by the action of said counter-balancing weights applied to the roof through said posts.

6. In a storage container for gas or liquid, in combination, an open top tank, an expansion roof for said tank adapted to have vertical movement with respect thereto to vary the vapor space within the tank, means providing a seal between the tank and roof so as to confine vapors within the tank, supporting means fixed to the cylindrical wall of the tank in spaced relation vertically thereof and being directed inwardly of the tank, a plurality of posts fixed to the roof at circumferentially spaced points and depending within the tank in associated relation with said supporting means, a plurality of sheaves'supported by each said supporting means and positioned adjacent the depending posts respectively, flexible means for maintaining the expansion roof substantially horizontal during movement thereof including cables extending diametrically within the tank and having contact with certain sheaves at points intermediate their ends, each cable at one end passing under a sheave and being secured to the roof and at its other end passing over a sheave and depending downwardly for connection with a depending post, a plurality of counter-balancing weights for said expansion roof, and flexible means supporting each weight and passing over a certain other sheave for connection with its respective depending post, whereby the roof is urged upwardly by the action of said counter-balancing weights applied to the roof through said posts.

7. In a storage container for gas or liquid, in combination, an open top tank, an expansion roof for said tank adapted to have vertical movement with respect thereto to vary the vapor space within the tank, means providing a seal between the tank and roof so as to confine vapors within the tank, supporting means fixed to the cylindrical wall of the tank in spaced relation vertically thereof and being directed inwardly of the tank, a plurality of posts fixed to the roof at circumferentially spaced points and depending within the tank in associated relation with said supporting means, a plurality of sheaves supported by each said supporting means and positioned adjacent the depending posts respectively, flexible means for maintaining the expansion roof substantially horizontal during movement thereof including cables extending diametrically within the tank and having contact at points intermediate their ends with sheaves provided by the upper supporting means, each cable at one end passing under a sheave and being secured to the roof and at its other end passing over a sheave and extending vertically downward for connec tion with a depending post, and counter-balancing means for the roof including weights and cables for connecting the weights with their respective depending post, each said last mentioned cable passing over a sheave provided by the lower supporting means.

- PHILIP S. GRAVER. 

